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Wednesday 8 May 2013

The electrostatic force on a small sphere of charge 0.4 µC due to another small sphere of charge − 0.8 µC in air is 0.2 N.


Question 2:
The electrostatic force on a small sphere of charge 0.4 µC due to another small  sphere of charge − 0.8 µC in air is 0.2 N. (a) What is the distance between the two spheres? (b) What is the force on the second sphere due to the first?
Solution:
(a) What is the distance between the two spheres?
Given that 
The electrostatic force on a small sphere of charge 0.4 µC due to another small  sphere of charge − 0.8 µC in air is 0.2 N.
Charge on first small sphere,     q1 =     0.4 µC =   0.4 × 10−6 C
Charge on second small sphere, q2 = − 0.8 µC = − 0.8 × 10−6 C
(1µC = 10 – 6C    so multiply by 10- 6   there)
The electrostatic force on a small sphere, F = 0.2 N 
Apply Coulomb’s law

Coulomb’s law
q1 = first charge
q2 = Second charge
r = distance between both charge
ε0= permittivity of free space
1/4πε0  = 9 × 109 Nm2C-2
Plug the values we get 
The distance between the two spheres is 0.12 m.

3 comments:

  1. I know its a free helping guide and i should not complaint about it but where is part(b) of this question ?? :/

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  2. How was -0.8 taken as 8 pls help me

    ReplyDelete